Seismic behavior of steel frames with different joints: Shaking table test and finite element analysis

This paper discusses the effect of different joint types (common joint (CJ), reduced beam section joint (RJ), and cover plate joint (CPJ)) on the seismic behavior of steel frames. Three steel frames (1:2 scale) with different joints were tested under the shaking table. El Centro wave was selected as the input seismic wave. The failure modes, dynamic response, displacement response, strain response, and acceleration response of steel frame specimens under five peak ground accelerations (PGA) were measured and analyzed. The experimental results indicated that the seismic damage of the steel frame specimens was mainly concentrated at the beam-column joints on the first story. The plastic hinge could be achieved shift-away by reinforcing and reducing the flange at the beam end and significantly improving the structure's seismic capacity. In addition, the ductile joints used also affected the overall structural stiffness. The steel frame specimens' dynamic response (seismic shear coefficient, structural capacity curve, and fundamental frequency attenuation curve) was discussed. As the dynamic loading was applied, the seismic shear coefficients of CPJ and RJ steel frame increased continuously, and the structural capacity curves rose steadily, which indicated that the RJ and CPJ had excellent seismic performance and ductility. The finite element analysis was performed to elaborate further on the seismic performance and failure modes of steel frames. The experimental results were verified by the finite element analysis, and the finite element model could be used for the subsequent research on the steel frame.